In the winamp display preferences, you can change the font size. As for as the actual font, you will need to change that in the pledit.txt file, however, Im not exactly sure of the syntax you'd need to use.
Awesome skin! This has to be the best classic skin I have seen in a long time and I've been using Winamp for a very long time. This skin I'll use till i no longer use winamp. The best reason I love this skin is its a simple,sleek, and those buttons to minimize and exit and so forth are easy to click. Where as Most of the other skins like these have such tiny ass exit/minimize buttons that I have to sit there and look close to make sure I don't hit exit. This skin is win. A white version wouldn't be a bad idea but no matter this is my default skin.